<template>
  <div class="app-container">
    <el-form label-width="120px">
      <el-form-item label="信息描述">
        <el-tag type="info">excel模版说明</el-tag>
        <el-tag>
          <i class="el-icon-download"/>
          <!--<a :href="excelUrl">点击下载模版</a>-->  <!-- 使用OSS存储 -->
          <!--<a href="/static/课程分类列表模板.xls">点击下载模版</a>-->  <!-- 存储在本地 -->
          <a :href="imgUrl" download="avatar-boy.gif">点击下载模版</a>
        </el-tag>

      </el-form-item>

      <el-form-item label="选择Excel">

        <el-upload
          ref="upload"
          :auto-upload="false"
          :on-success="fileUploadSuccess"
          :on-error="fileUploadError"
          :on-change="handleChange"
          :disabled="importBtnDisabled"
          :limit="1"
          :file-list="fileList"
          :action="BASE_API+'/admin/edu/subject/import'"
          name="file"
          accept="application/vnd.ms-excel">  <!-- 限制文件类型为excel -->
          <el-button slot="trigger" size="small" type="primary">选取文件</el-button>
          <el-button
            :loading="loading"
            style="margin-left: 10px;"
            size="small"
            type="success"
            @click="submitUpload">{{ fileUploadBtnText }}
          </el-button>
        </el-upload>

      </el-form-item>
    </el-form>

  </div>
</template>

<script>
export default {
  data() {
    return {
      BASE_API: process.env.BASE_API, // 接口API地址
      OSS_PATH: process.env.OSS_PATH, // 阿里云OSS地址
      fileUploadBtnText: '上传到服务器', // 按钮文字
      importBtnDisabled: false, // 按钮是否禁用,
      loading: false,
      fileList: [],
      excelUrl: process.env.OSS_PATH + '/execl/' + decodeURIComponent('课程分类列表模板') + '.xls',
      imgUrl: process.env.OSS_PATH + '/avatar/avatar-boy.gif'
    }
  },

  methods: {
    // 文件状态改变时的钩子，添加文件、上传成功和上传失败时都会被调用
    handleChange(file, fileList) {
      this.fileList = fileList
    },

    // 提交表单的方法
    submitUpload() {
      if (this.fileList.length <= 0) {
        this.$message({
          type: 'warning',
          message: '请选择一个文件上传'
        })
        return false
      }
      this.fileUploadBtnText = '文件正在上传'
      this.importBtnDisabled = true
      this.loading = true
      this.$refs.upload.submit()
    },

    // 上传成功回调
    fileUploadSuccess(response) {
      if (response.success === true) {
        this.fileUploadBtnText = '导入成功'
        this.importBtnDisabled = false
        this.loading = false

        this.$message({
          type: 'success',
          message: response.message
        })
        console.log(this.$refs.upload)
        this.$router.push({ path: '/edu/subject' })
      } else {
        this.fileUploadBtnText = '导入失败'
        this.importBtnDisabled = false
        this.loading = false

        const messages = response.data.errorMsgList
        let msgString = '<ul style="list-style-type: none">'
        messages.forEach(msg => {
          msgString += `<li>${msg}</li>`
        })
        msgString += '</ul>'
        this.$alert(msgString, response.message, {
          dangerouslyUseHTMLString: true, // 渲染返回值中的html
          callback: action => {
            this.fileList = []
          }
        })
      }
    },

    // 上传失败回调
    fileUploadError(response) {
      this.fileUploadBtnText = '导入失败'
      this.loading = false
      this.$message({
        type: 'error',
        message: '导入失败'
      })
    }
  }
}
</script>
